It is well known to insulate buildings using various types of insulating materials including mineral fibers such as fibrous glass wools. Processes for forming the fibers generally include forcing a molten glass composition through orifices in an outer wall of a centrifuge or spinner to produce relatively short, straight glass fibers. Typically a binder is added to the fibers prior to their collection in substantially planar layers. The binder after curing secures the fibers together to create a unitary piece of the insulating material.
The insulating material after curing is typically mechanically shaped and cut into a blanket or batt having a predetermined cross-sectional shape such as a rectangle. An exterior layer or facing is often secured to the batt to facilitate the ease of installing and handling of the insulation assemblies. After cutting these insulation assemblies are particularly suited for immediate installation between wall studs and ceiling and floor joists which are spaced apart a distance corresponding to the width of the assemblies. The term "joists" as used within this application will be understood to include studs, joists and other framing elements and structures between which insulation assemblies are positionable.
Insulation assemblies using short fibered batts that are bindered and thus relatively rigid have several disadvantages. First they cannot conform to variations in the spaces in which they are installed. The spaces between joists that receive these insulation assemblies often contain abnormal voids and other non-uniformities created by electrical wiring, plumbing lines, ducts and the like disposed in between the joists. In using the short fibered insulation assemblies the user either has to be content with gaps or voids in the insulation coverage or, alternatively, cut the insulation to fit.
In fact the prior art discloses methods for reducing at least some of the time and effort of the installer. U.S. Pat. No. 4,866,905 discloses for example a mineral fiber strip with laterally extending marking lines. An installer cuts along the lines to select a desired width of the product for installation. Similarly, U.S. Pat. No. 968,681 to Stokes and U.S. Pat. No. 1,238,356 to Paddack show cotton wadding strips of a substantial length and width. Longitudinal partial cuts extend along the length of the cotton wadding. These cuts facilitate cutting smaller width strips from the wadding by the user.
Providing partial cuts or marking lines can thus facilitate the cutting of insulation assemblies into desired sizes. They do not however eliminate the need to cut these insulation assemblies into desired shapes and sizes to fit them into non-traditionally sized areas, voids, and around abnormalities.
An additional problem with the short fibered, bindered insulation assemblies arises from the fact that they are designed and manufactured for installation in a particular spaced aperture. Since most framing has a standard or traditional size of either 16 inches or 24 inches between joists, manufacturers typically make products with both these widths. Most manufacturers, to meet the needs of users, make products with these widths in various heights and/or densities to enable the users to have desired R-value insulation installed. (R-value is a standard measure of the efficiency of insulation, or its thermal resistivity.)
However, many users have needs for installation of insulation assemblies of different sizes or different R-values. This plethora of product needs requires retailers of the insulation assemblies to commit a large amount of space to them in order to carry an entire product line. Understandably many sellers opt not to carry all of the sizes. This is particularly true of those sizes for which there is less or slower demand.
Thus users may not be able to locate an appropriately sized product because the manufacturer does not make it or the retailers the user locates do not stock it. In these instances the user must attempt to cut the insulation assembly to the appropriate size, seek an alternative type of insulation product, accept decreased efficiency by leaving gaps and spaces, or use additional insulation to overlay the joists, if possible.
One alternative form of insulation is loose fill products. These products have no performed shape and consist of individual groups of insulation fibers that are inserted into the space to be insulated. Installation of this form of insulation typically comprises blowing the fibers into a desired space. Thus the insulation does not have to be cut or otherwise sized for installation. However, the loose fill is difficult to handle, requires special equipment to install and may leave gaps or voids if not properly installed. Further, loose fill does not always achieve consistent coverage of the spaces in which it is installed (the density of the insulation material varies as installed and it may in some instances shift or compact over time). Loose fill also commonly has airborne particles that may irritate the skin and breathing passages of users.
An alternative wool insulation product recently developed overcomes some of the disadvantages of the short fibered products. U.S. Pat. No. 5,508,079 to Grant and Berdan describes this assembly and the method for making it. Specifically, Grant et al. disclose a process for the manufacture of a binderless, fibrous glass wool insulation. The process includes forming substantially long glass fibers that make up about 20 percent or more of the weight or number of all fibers. The fibers of these insulation assemblies upon formation are oriented in a spiral fashion and then mechanically shaped to produce a batt of a predetermined size and density. Securing an exterior layer, preferably formed of polyethylene that closely conforms to the perimeter of the batt, completes the insulation assembly.
The insulation assembly disclosed by Grant et al. provides a substantial advantage over the short fibered, bindered insulation assemblies of the prior art. These insulation assemblies, being less rigid, enable the user to conform the insulation assembly to occupy the voids frequently found between joists. The user merely conforms the batt to fill small voids and to adjust around the presence of items between the joists. It also enables the user to have greater portions of the assembly extend over the joist to directly abut adjacent insulation assemblies with reduced void spacing over the joists compared to short fibered, bindered insulation assemblies.
The conformable feature of this type of insulation assembly eliminates many instances of cutting the assembly as compared with the short fibered, bindered insulation assemblies. Thus the conformable insulation assembly disclosed by Grant et al. provides a more convenient product for users. Nevertheless the conformable insulation assembly disclosed by Grant et al., like the short fibered, bindered products of the prior art, has some limitations. The conformable insulation assemblies as made and sold by Owens Corning under the trademark MIRAFLEX.TM. are adapted for installation in particular sized areas having a predetermined nominal width. The products as manufactured also have a standard thickness and/or density to provide a predetermined level of insulation given by the R-value. Thus, the manufacturer of these products must generally provide a plurality of products of different widths, e.g., 16 inch and 24 inch wide products. Additionally for each of these products the manufacturer must provide products having different heights and/or densities to provide different R-values of insulation assemblies for the user.
This necessarily means that the manufacturer of this type of insulation product must make a plethora of products to met the needs of most users. Nevertheless the needs of many users who need insulation to fit non-traditional joist spaces (e.g., 19.2 inches) or need non-standard insulation efficiency are still left with no choice but to cut these products, seek an alternative form of insulation, install overlying insulation assemblies or accept less efficient results. Additionally the retailers and distributors of these products may choose not to stock or carry products for which there is not high demand given the space and volume constraints of their businesses. Thus in some cases even when a suitably sized or R-value product exists, the user may not be able to locate it.
Thus a need exists for an insulation assembly that can be relatively easily reshaped and installed by the user to meet the specific size requirements of the user. A need also exists for an insulation assembly that can be reshaped to provide different R-value coverage of areas. A further need exists for a reshapable insulation assembly and a method of use that reduces the number of discrete products needed to be manufactured and to be carried by retailers and distributors. A further need also exists for providing an insulation assembly and method of use that provides the user with increased utility or options for installation.